There are two typical approaches to overcome this shortcoming. In the first approach non-renormalizable operators are added, while the same minimal field content is used (see e.g. [1]}, [2]}, [3]}, [4]}). For the second approach new fields are added to the minimal field content, while the renormalizability of the model is preserved. These added fields either allow the introduction of additional new renormalizable operators (see e.g. [5]}, [6]}) such that Eq. (REF ) no-longer holds, or change the renormalization group evolution of \(\textbf {Y}_e\)  and \(\textbf {Y}_d\) , while Eq. (REF ) is maintained at the GUT scale. The latter is very challenging, especially for the second family. In the former cases extra degrees of freedom are added and thus predictivity for the GUT scale Yukawa ratios is lost.
